These rules do NOT apply to monsters with the text “When this card destroys an opponent’s monster by battle….” (but does not specify “and sends it to the Graveyard”). (Example: “Blue Thunder T-45”.) Monsters with that text will activate their effects in ALL of the above scenarios.

OCG Rulings

Returning this card to the Deck is a cost to activate the effect which Special Summons a different "Gladiator Beast" monster.[1]

Judge Program Forum Rulings

These Ruling(s) have not been confirmed as applicable to the TCG.[Notes 1]

If both players are about to activate a Gladiator Beast's effect(s) during the End Step of the Battle Phase, since each of these effects resolve independently of each other, then, similar to resolving effects during the Standby Phase and End Phase, the turn player may resolve one or more of his effects before the opponent will get to resolve theirs. Turn player will be able to resolve one of his effects or pass Priority to the opponent, who will then be able to resolve on [sic] of his effects.[3]

OCG Rulings

When "Gladiator Beast Alexander" etc. battles, if it is flipped face-down and then flipped face-up before the end of the Battle Phase, then you cannot activate the effect which Special Summons another "Gladiator Beast" monster from your Deck.[5]

If you gain control of your opponent's "Gladiator Beast Alexander" etc. and it battles, then at the end of the Battle Phase you can activate its effect. "Gladiator Beast Alexander" etc. is shuffled into your opponent's Deck, but you activated the effect, so you Special Summon a "Gladiator Beast" monster from your Deck. However, you cannot activate the effect of "Gladiator Beast Alexander" etc. if you do not have a "Gladiator Beast" monster in your Deck that you can Special Summon.[11]

Previously Official Rulings

These TCG rulings were issued by Upper Deck Entertainment and have since been deemed unofficial by Konami.[19] They were previously considered official, but may or may not necessarily hold true nowadays.

If a “Gladiator Beast” monster attacks or is attacked during the Battle Phase and the “Gladiator Beast” monster becomes flipped face-down by an effect during the Battle Phase, even if the “Gladiator Beast” monster is flipped face-up before the end of the Battle Phase its effect to Special Summon another “Gladiator Beast” monster cannot be activated.[20]

If 2 or more “Gladiator Beast” monsters attack or are attacked during the Battle Phase, at the end of the Battle Phase the effect of each “Gladiator Beast” monster can be activated. The effects will activate and resolve separately. They are not combined onto the same Chain.[20]

If you take control of your opponent's "Gladiator Beast" monster and attack with it during the Battle Phase, you can return it to your opponent's Deck to Special Summon a "Gladiator Beast" monster from your Deck if you have a "Gladiator Beast" monster in your Deck that you can Special Summon.. [sic][20]

Mentions in Other Rulings

Disarm: The “Gladiator Beast” monster returned to the Deck is returned to the Deck when “Disarm” is resolved. It is not a cost. You must show the “Gladiator Beast” to your opponent when resolving “Disarm's” effect.

Parry: The "Gladiator Beast" monster returned to the Deck is returned to the Deck when "Parry" is resolved. It is not a cost. You must show the "Gladiator Beast" to your opponent when resolving "Parry's" effect.

Notes

↑Konami Judge Program Rulings are considered unverified, as their source(s) are not publicly viewable. They are not confirmed as applicable to the TCG until they have been officially published by Konami.

↑Konami FAQ: When "Gladiator Beast Alexander" battles and is flipped face-down, then can you activate the Special Summoning effect?

↑Konami FAQ: Can the effect of "Gladiator Beast Alexander" be activated if there is no "Gladiator Beast" monster in your Deck?

↑Konami FAQ: When "Gladiator Beast Alexander" etc. is destroyed by battle, can the effect which Special Summons be activated?

↑Konami FAQ: Can "Divine Wrath" be activated against the effect of "Gladiator Beast Alexander" etc. which Special Summons a "Gladiator Beast" monster?

↑Konami FAQ: Is returning "Gladiator Beast Alexander" etc. to the Deck a cost to activate the effect?

↑Konami FAQ: When "Gladiator Beast Alexander" etc. battles during an opponent's turn, can you activate the effect which Special Summons a "Gladiator Beast" monster from your Deck?

↑Konami FAQ: When you gain control of a "Gladiator Beast Alexander" and you activate its effect, how do you resolve it?

↑Konami FAQ: When a monster equipped with "Double Tool C&D" attacks a "Gladiator Beast" monster, can another "Gladiator Beast" monster be Special Summoned?

↑Konami FAQ: When a "Gladiator Beast" monster battles after "Ancient Forest" was activated, does either effect resolve?

↑Konami FAQ: If the effect of "Rivalry of Warlords" is active, then can you activate the effect of "Gladiator Beast Laquari" and Special Summon a "Gladiator Beast" monster of a different Type?

↑ 15.015.1Konami FAQ: Can the effect of a monster like "Gladiator Beast Alexander" be activated if the opponent's battling monster is destroyed when "Gladiator Beast War Chariot" is activated during the Damage Step?

↑Konami FAQ: When the Special Summoning effect of a "Gladiator Beast" monster activates at the end of the Battle Phase, at what time do you activate "Royal Oppression" to negate it?

↑ 17.017.117.2Konami FAQ: At the end of the Battle Phase, if the effects of multiple "Gladiator Beast" monsters activate, then in what order do they activate?

↑Konami FAQ: Can "Majestic Star Dragon" activate the effect of a negated "Gladiator Beast" to Special Summon a monster from the Deck?